Stitch Repeat Calculator
Patterns often need a stitch count that's "a multiple of X, plus Y" — this finds the nearest valid count to your target width, for crochet or knitting alike.
Why patterns write repeats this way
A stitch pattern that repeats every 12 stitches needs a total stitch count that's an exact multiple of 12 to repeat cleanly all the way across a row, with no partial, cut-off repeat at the edge. The "plus 3" (or whatever extra number a pattern states) usually accounts for edge or selvedge stitches needed to keep the pattern looking balanced and symmetrical at both ends, rather than starting mid-repeat on one side. This notation shows up constantly in both crochet (shell stitch, cluster stitch, granny stripes) and knitting (cable panels, lace, rib patterns) — the math is identical either way, only the stitches themselves differ.
Rounding down vs rounding up
Rounding down gets you closer to your original target width but slightly narrower; rounding up gets you a slightly wider piece that still fits the repeat. Neither is "more correct" — it depends on whether your project can tolerate being a little smaller or a little bigger than planned. For a garment where fit matters precisely, round toward whichever direction keeps you closer to the ease you want; for a blanket or scarf where an inch either way doesn't matter, rounding down usually saves a little yarn.
Multiple repeats in one piece
Some patterns have more than one repeat active in different sections — a border repeat plus a different main-body repeat, for instance. Run this calculator once per section using each section's own repeat numbers rather than trying to satisfy both repeats with a single combined count, which usually isn't mathematically possible unless the two repeat numbers share a clean common multiple.